1. Field of the Invention
The present invention relates to the general field of portable lighting devices and, more specifically, to a flashlight having substantially permanent luminescence not requiring an external energy source to stimulate the luminescence. It also optionally includes a housing sized to receive one or more batteries. One of the embodiments includes a square cross-section battery tube insert to fit into the housing to receive batteries smaller than the inside diameter of the housing to leave an annular floatation air space within the housing to make the flashlight buoyant.
2. Description of Prior Art
Ever since the invention of portable electrical storage batteries, it is been practical to carry around portable lighting devices which use incandescent bulbs as the light source. The most relevant reference that has been located is Pemberton, U.S. Pat. No. 4,546,416, which describes a flashlight in combination with phosphorescent material. However, the phosphorescent material must be rejuvenated by exposure to light at frequent intervals, a shortcoming overcome by the present invention because of its substantially permanent luminescence. Other prior art includes Pietruczynik, et al., U.S. Pat. No. 5,752,761, Sato, U.S. Pat. No. 5,757,111, McDermick, U.S. Pat. No. 5,842,777, McDermick, U.S. Pat. No. 5,161,879, Maglica, U.S. Pat. No. 5,260,858, Price, III, U.S. Pat. No. 4,843,526, Sharrah, et al., U.S. Pat. No. 5,853,241, et al., Maglica U.S. Pat. No. 5,836,672, Maglica, U.S. Pat. No. 5,528,472 and numerous other references. So far as is known no reference combines a flashlight with a substantially permanent luminescent housing.